FontFace AddFontFaceToCache()
{
FontFace fontFace = CreateFontFace();
FontFace bumpedFontFace = null;
// NB: if the cache is busy, we simply return the new FontFace
// without bothering to cache it.
if (Interlocked.Increment(ref _mutex) == 1)
{
if (null == _fontFaceCache)
{
_fontFaceCache = new FontFaceCacheEntry[_fontFaceCacheSize];
}
// Default to a slot that is not the MRU.
_fontFaceCacheMRU = (_fontFaceCacheMRU + 1) % _fontFaceCacheSize;
// Look for an empty slot.
for (int i = 0; i < _fontFaceCacheSize; i++)
{
if (_fontFaceCache[i].font == null)
{
_fontFaceCacheMRU = i;
break;
}
}
// Keep a reference to any discarded entry, clean it up after releasing
// the mutex.
bumpedFontFace = _fontFaceCache[_fontFaceCacheMRU].fontFace;
// Record the new entry.
_fontFaceCache[_fontFaceCacheMRU].font = this;
_fontFaceCache[_fontFaceCacheMRU].fontFace = fontFace;
fontFace.AddRef();
}
Interlocked.Decrement(ref _mutex);
// If the cache was full and we replaced an unreferenced entry, release it now.
if (bumpedFontFace != null)
{
bumpedFontFace.Release();
}
return(fontFace);
}
FontFace LookupFontFaceSlow()
{
FontFace fontFace = null;
for (int i = 0; i < _fontFaceCacheSize; i++)
{
if (_fontFaceCache[i].font == this)
{
fontFace = _fontFaceCache[i].fontFace;
fontFace.AddRef();
_fontFaceCacheMRU = i;
break;
}
}
return(fontFace);
}